Dark Sun: The Scorched World of Athas
When night falls, the dead stir. Griefmotes are tiny sparks of unliving, glowing orbs that chill the flesh and rend the mind. When an innocent dies, sometimes a spirit fragment survives the soul’s migration from the flesh to the the Gray. These fragments preserve the victim’s final suffering.
Griefmotes lurk invisibly, converging on living victims undetected so they can use chill of the grave to chip away at their foes’ defenses. Once a foe becomes vulnerable to cold, they use chilling touch and use invisibility to dart away undetected.